GRUB not appearing after update on iMac

[salvocos]

After some updates GRUB window does not appear anymore on my imac.

I am currently running kernel 5.1.19-1.

Before I make any changes I just wanted to be sure these would not brake the installation.
I was wondering if changing the partition flags would help in way.

The /boot/efi/EFI/ directory already exists.
I was wondering if changing the flags using gparted would help.
Following is the partitions list,

And the flags for the bootable partition

I was wondering if setting the bios_grub flag would help.
Following are the kernel parameters:
quiet radeon.dpm=0 acpi_backlight=vendor

Thanks a lot for your help

[bogdancovaciu]

But does the system boot? If you press Shift or Esc after the chime sound, does the Grub Menu appear? If you hold the Command can you select the mac hdd and boot into MacOS?

[stephane]

any Update by Apple or Select Disks to boot an os X will suppress any entry EFI other than os x
restart with USB install manjaro , select your partition disk and boot

can you provide

sudo efibootmgr -v

[salvocos]

@bogdancovaciu Yes, it does appear if I press Esc after the chime sound!
I have to say I would be happy enough with this behavior, thanks a lot.

[salvocos]

@stephane, I am able to see the menu using the Esc (I know I should have known that..)

I am attaching anyway the output from the command

BootCurrent: 0000
Timeout: 5 seconds
BootOrder: 0000,0080
Boot0000* Manjaro	HD(1,GPT,2732e2f3-4b31-41f4-91e8-350f93946977,0x28,0x64000)/File(\EFI\Manjaro\grubx64.efi)
Boot0080* Mac OS X	PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0,0,0)/HD(2,GPT,1a07d900-15bb-445a-a47e-8f759eed2121,0x64028,0x746a2d60)/VenMedia(be74fcf7-0b7c-49f3-9147-01f4042e6842,14c945c2ddd1744fbf594453e24906ce)/File(\F8C1355F-32C3-4FF5-89FB-BAD1F0777D4C\System\Library\CoreServices\boot.efi)
Boot0081* Mac OS X	PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0,0,0)/HD(2,GPT,1a07d900-15bb-445a-a47e-8f759eed2121,0x64028,0x746a2d60)/VenMedia(be74fcf7-0b7c-49f3-9147-01f4042e6842,14c945c2ddd1744fbf594453e24906ce)/File(\F8C1355F-32C3-4FF5-89FB-BAD1F0777D4C\System\Library\CoreServices\boot.efi)
BootFFFF* 	PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0,0,0)/HD(2,GPT,1a07d900-15bb-445a-a47e-8f759eed2121,0x64028,0x746a2d60)/VenMedia(be74fcf7-0b7c-49f3-9147-01f4042e6842,14c945c2ddd1744fbf594453e24906ce)/File(\2B460E59-01DE-3F07-B64D-E4431C414A5B\com.apple.installer\boot.efi)

Thanks a lot

[stephane]

try on boot with ALT to appears EFI boot
as apfs is a new format partition , grub only see hfs+ , maybe the trouble here

or you boot from USB with select disk partition